class Solution {
public:
    int search(vector<int>& nums, int target) {
        int n = nums.size();
        if (n == 1 && nums[0] == target) return 0;
        else if (n == 1 && nums[0] != target) return -1;
        int left = 0, right = n - 1;
        while (left <= right) {
            int mid = left + (right - left) / 2;
            if (nums[mid] > target) {
                right = mid - 1;
            }
            else if (nums[mid] < target) {
                left = mid + 1;
            }
            else return mid;
        }
        return -1;
    }
};